From: Ido Schimmel idosch@mellanox.com
[ Upstream commit c4317b11675b99af6641662ebcbd3c6010600e64 ]
In case devlink reload failed, it is possible to trigger a use-after-free when querying the kernel for device info via 'devlink dev info' [1].
This happens because as part of the reload error path the PCI command interface is de-initialized and its mailboxes are freed. When the devlink '->info_get()' callback is invoked the device is queried via the command interface and the freed mailboxes are accessed.
Fix this by initializing the command interface once during probe and not during every reload.
This is consistent with the other bus used by mlxsw (i.e., 'mlxsw_i2c') and also allows user space to query the running firmware version (for example) from the device after a failed reload.
[1] BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline] BUG: KASAN: use-after-free in mlxsw_pci_cmd_exec+0x177/0xa60 drivers/net/ethernet/mellanox/mlxsw/pci.c:1675 Write of size 4096 at addr ffff88810ae32000 by task syz-executor.1/2355
CPU: 1 PID: 2355 Comm: syz-executor.1 Not tainted 5.8.0-rc2+ #29 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xf6/0x16e lib/dump_stack.c:118 print_address_description.constprop.0+0x1c/0x250 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x14e/0x1b0 mm/kasan/generic.c:192 memcpy+0x39/0x60 mm/kasan/common.c:106 memcpy include/linux/string.h:406 [inline] mlxsw_pci_cmd_exec+0x177/0xa60 drivers/net/ethernet/mellanox/mlxsw/pci.c:1675 mlxsw_cmd_exec+0x249/0x550 drivers/net/ethernet/mellanox/mlxsw/core.c:2335 mlxsw_cmd_access_reg drivers/net/ethernet/mellanox/mlxsw/cmd.h:859 [inline] mlxsw_core_reg_access_cmd drivers/net/ethernet/mellanox/mlxsw/core.c:1938 [inline] mlxsw_core_reg_access+0x2f6/0x540 drivers/net/ethernet/mellanox/mlxsw/core.c:1985 mlxsw_reg_query drivers/net/ethernet/mellanox/mlxsw/core.c:2000 [inline] mlxsw_devlink_info_get+0x17f/0x6e0 drivers/net/ethernet/mellanox/mlxsw/core.c:1090 devlink_nl_info_fill.constprop.0+0x13c/0x2d0 net/core/devlink.c:4588 devlink_nl_cmd_info_get_dumpit+0x246/0x460 net/core/devlink.c:4648 genl_lock_dumpit+0x85/0xc0 net/netlink/genetlink.c:575 netlink_dump+0x515/0xe50 net/netlink/af_netlink.c:2245 __netlink_dump_start+0x53d/0x830 net/netlink/af_netlink.c:2353 genl_family_rcv_msg_dumpit.isra.0+0x296/0x300 net/netlink/genetlink.c:638 genl_family_rcv_msg net/netlink/genetlink.c:733 [inline] genl_rcv_msg+0x78d/0x9d0 net/netlink/genetlink.c:753 netlink_rcv_skb+0x152/0x440 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:764 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x53a/0x750 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x850/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0x150/0x190 net/socket.c:672 ____sys_sendmsg+0x6d8/0x840 net/socket.c:2363 ___sys_sendmsg+0xff/0x170 net/socket.c:2417 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2450 do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: a9c8336f6544 ("mlxsw: core: Add support for devlink info command") Signed-off-by: Ido Schimmel idosch@mellanox.com Reviewed-by: Jiri Pirko jiri@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlxsw/pci.c | 54 ++++++++++++++++------- 1 file changed, 38 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c index f3d1f9411d104..aa4fef7890841 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/pci.c +++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c @@ -1401,23 +1401,12 @@ static int mlxsw_pci_init(void *bus_priv, struct mlxsw_core *mlxsw_core, u16 num_pages; int err;
- mutex_init(&mlxsw_pci->cmd.lock); - init_waitqueue_head(&mlxsw_pci->cmd.wait); - mlxsw_pci->core = mlxsw_core;
mbox = mlxsw_cmd_mbox_alloc(); if (!mbox) return -ENOMEM;
- err = mlxsw_pci_mbox_alloc(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); - if (err) - goto mbox_put; - - err = mlxsw_pci_mbox_alloc(mlxsw_pci, &mlxsw_pci->cmd.out_mbox); - if (err) - goto err_out_mbox_alloc; - err = mlxsw_pci_sw_reset(mlxsw_pci, mlxsw_pci->id); if (err) goto err_sw_reset; @@ -1524,9 +1513,6 @@ static int mlxsw_pci_init(void *bus_priv, struct mlxsw_core *mlxsw_core, mlxsw_pci_free_irq_vectors(mlxsw_pci); err_alloc_irq: err_sw_reset: - mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.out_mbox); -err_out_mbox_alloc: - mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); mbox_put: mlxsw_cmd_mbox_free(mbox); return err; @@ -1540,8 +1526,6 @@ static void mlxsw_pci_fini(void *bus_priv) mlxsw_pci_aqs_fini(mlxsw_pci); mlxsw_pci_fw_area_fini(mlxsw_pci); mlxsw_pci_free_irq_vectors(mlxsw_pci); - mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.out_mbox); - mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); }
static struct mlxsw_pci_queue * @@ -1755,6 +1739,37 @@ static const struct mlxsw_bus mlxsw_pci_bus = { .features = MLXSW_BUS_F_TXRX | MLXSW_BUS_F_RESET, };
+static int mlxsw_pci_cmd_init(struct mlxsw_pci *mlxsw_pci) +{ + int err; + + mutex_init(&mlxsw_pci->cmd.lock); + init_waitqueue_head(&mlxsw_pci->cmd.wait); + + err = mlxsw_pci_mbox_alloc(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); + if (err) + goto err_in_mbox_alloc; + + err = mlxsw_pci_mbox_alloc(mlxsw_pci, &mlxsw_pci->cmd.out_mbox); + if (err) + goto err_out_mbox_alloc; + + return 0; + +err_out_mbox_alloc: + mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); +err_in_mbox_alloc: + mutex_destroy(&mlxsw_pci->cmd.lock); + return err; +} + +static void mlxsw_pci_cmd_fini(struct mlxsw_pci *mlxsw_pci) +{ + mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.out_mbox); + mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox); + mutex_destroy(&mlxsw_pci->cmd.lock); +} + static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { const char *driver_name = pdev->driver->name; @@ -1810,6 +1825,10 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) mlxsw_pci->pdev = pdev; pci_set_drvdata(pdev, mlxsw_pci);
+ err = mlxsw_pci_cmd_init(mlxsw_pci); + if (err) + goto err_pci_cmd_init; + mlxsw_pci->bus_info.device_kind = driver_name; mlxsw_pci->bus_info.device_name = pci_name(mlxsw_pci->pdev); mlxsw_pci->bus_info.dev = &pdev->dev; @@ -1827,6 +1846,8 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) return 0;
err_bus_device_register: + mlxsw_pci_cmd_fini(mlxsw_pci); +err_pci_cmd_init: iounmap(mlxsw_pci->hw_addr); err_ioremap: err_pci_resource_len_check: @@ -1844,6 +1865,7 @@ static void mlxsw_pci_remove(struct pci_dev *pdev) struct mlxsw_pci *mlxsw_pci = pci_get_drvdata(pdev);
mlxsw_core_bus_device_unregister(mlxsw_pci->core, false); + mlxsw_pci_cmd_fini(mlxsw_pci); iounmap(mlxsw_pci->hw_addr); pci_release_regions(mlxsw_pci->pdev); pci_disable_device(mlxsw_pci->pdev);